This invention relates broadly and generally to fluid (e.g., air) filters for residential, commercial, and industrial applications. In one exemplary embodiment, the invention comprises a deep pleated air filter assembly incorporating a unique truncated pyramidal frame design. The present pyramidal frame design allows the filter assembly to be installed in standard 1 and 2 inch nominal filter grills used in most residential and commercial applications, while providing greatly increased media area compared to standard air filter products.
Most residential or commercial air filter applications incorporate a nominal 1 or 2 inch thick air filter. With the concern over the quality of the air that we breathe, increased efficiency air filter media have been developed and adopted by many air filter manufacturers. Typically, as air filter efficiency increases more media area is required to increase air flow through the filter (reduce pressure drop across the filter surface). Air filters with high pressure drop result in high energy consumption, as HVAC units work harder to achieve the desired room temperature.
Typically, the most direct approach of reducing air flow restriction is to add media surface area. For example, a pleated filter incorporates more media area than a flat panel filter. Increasing the pleat count per foot of filter length will also increase air filter media area. Current residential and commercial filter applications are limited when a large increase in filter media area is required. Specifically, filter manufacturers are limited in the amount of filter media that can be added in a 1 or 2 inch filter depth. Even with pleated media, bridging can occur when too much media is added, resulting in poor filter performance. Modifications to the existing filter grills or custom grill designs can provide the additional room required to accommodate larger air filter designs. In many cases however, extensive modifications to the HVAC systems are required.
The present invention addresses the challenge of increase media area while providing a simplified installation advantage. The unique frame design offers several advantages when compared to existing products. The invention installs in the same manner as most air filter applications and can be manufactured in paper, metal or plastic. The need for custom size filters may be reduce or substantially eliminated by the unique “wedge” frame design. An added benefit is an increased positive seal to the filter grill interface, thereby eliminating any significant air bypass. The invention also greatly increases the air filter media area. This increase in air filter media area allows for the use of more efficient filter media, and reduces air flow restriction thereby promoting longer filter life.